The purpose of this investigation was to determine the scale of the infection, route of transmission, and the relevant risk factors of a scarlet fever outbreak which occurred in early March, 2000, at a nursery in Taichung City . A structured questionnaire was used to interview 199 children (interview rate 87.6%). The questionnaire contained questions concerning personal background, date of disease onset, clinical symptoms, medical treatment, means of transportation to school,recent travel and similar symptoms in family members or friends. The 23 cases with suspected symptoms and contacts underwent laboratory testing for group A β-hemolytic streptococci. Of the children interviewed, five (two males and three females) were confirmed and three (all females) were suspected cases, yielding a total attack rate of 4% (8/199). Their symptoms were , in order of frequency: desquamation of skin of hands and feet 62.5% (5/8), rough skin and sore throat (37.5% each, 3/8), rash, strawberry tongue, fever (25.0% each, 2/8), and fatigue (12.5%, 1/8). Most infections occurred between March 6 and 16 while the index case appeared on 6 March. Of the 23 suspectd cases and contacts, five were found to be group A β-hemolytic streptococcus positive. The environment of the nursery was relatively clean. Ventilation was good. Air-conditioning was not used. Statistival analysis did not show any association between either the means of transportation to school or recent travel and the infection (p value of each >0.05). Epidemiologically, many cases were related in terms of time and space, their dates of onset were within the incubation period of scarlet fever ,therefore close personal contact was likely the major route of transmission.